Patent US5210685A successfully refreshed from Google Patents.
US5210685A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Uninterruptible power supply system and load transfer static switch for such a system
Assignee: Westinghouse Electric Corp
•
Filing: 1985-03-08
•
Granted: 1993-05-11
•
Expires: 2005-03-08
Abstract
Abstract A UPS system which operates initially in a commutation mode allowing commutation of the static transfer switch provided on the primary supply lines, and wherein the standby source is kept energized so as to operate to commutate such transfer switch through the inverter just before initiating UPS mode of operation.
Inventors
- 👤 John Rosa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:58
CPC Classifications
H; H02; H02J; H02J9/00; H02J9/04; H02J9/06; H02J9/062; Y; Y02; Y02B; Y02B70/00; Y02B70/30; Y04; Y04S; Y04S20/00; Y04S20/20
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
134 words
A UPS system including: a primary AC power supply connected to an AC load through a first static-controlled transfer switch, an auxiliary inverter and a standby DC voltage-source connected to said inverter, a second static-controlled transfer switch for connecting said inverter to said AC load, and means responsive to a critical event for disabling said first transfer switch and for enabling said second transfer switch; the inverter comprising gating means operative first in a commutation mode concurrently with said critical event responsive means for applying, through said inverter and through said second transfer switch, to said first transfer switch the voltage of said DC-source as a commutation voltage thereof; said inverter gating means being operative in a UPS mode after said commutation mode to generate an auxiliary AC power supply to the AC load.
Claim 2
Dependent Claim
134 words
A UPS system including: a primary AC power supply connected to an AC load through a first static-controlled transfer switch, an auxiliary inverter and a standby DC voltage-source connected to said inverter, a second static-controlled transfer switch for connecting said inverter to said AC load, and means responsive to a critical event for disabling said first transfer switch and for enabling said second transfer switch; the inverter comprising gating means operative first in a commutation mode concurrently with said critical event responsive means for applying, through said inverter and through said second transfer switch, to said first transfer switch the voltage of said DC-source as a commutation voltage thereof; said inverter gating means being operative in a UPS mode after said commutation mode to generate an auxiliary AC power supply to the AC load.
Claim 3
Dependent Claim
33 words
The UPS system of claim 1 with time delay means being provided for establishing a predetermined time delay for the duration of said commutation mode and for the initiation of said UPS mode.
Claim 4
Dependent Claim
47 words
The UPS system of claim 2, with means being provided for sensing the direction of current in said first transfer switch; said gating means being responsive to said sensing means for outputting with said inverter a commutation voltage of a polarity corresponding to the sensed current direction.
Claim 5
Dependent Claim
57 words
The UPS system of claim 3, with the inverter having power switches, said gating means being operated in the commutation mode to control selected ones of said inverter power switches, the selection of said selected inverter power switches being in accordance with the current direction sensed by said sensing means and corresponding to said commutation voltage polarity.
Claim 6
Dependent Claim
27 words
The UPS system of claim 4, with said second transfer switch comprising said selected inverter power switches under control of said gating means in the commutation mode.
Claim 7
Dependent Claim
14 words
The UPS system of claim 5, with said inverter power switches being GTO's switches.
Claim 8
Dependent Claim
13 words
The UPS system of claim 5, with said inverter power switches being transistors.
Claim 9
Dependent Claim
14 words
The UPS system of claim 5, with said first transfer switch including thyristor switches.
Claim 10
Dependent Claim
50 words
The UPS system of claim 8, with means synchronized with said primary AC power supply for generating a reference voltage signal characterizing said AC load, said gating means in the UPS mode being responsive to said reference voltage signal for controlling said inverter to generate said auxiliary AC power supply.
Claim 11
Dependent Claim
51 words
The UPS system of claim 9, with means for sensing actual AC voltage at the input of said AC load for deriving a signal representative of said actual AC voltage, comparator means being provided responsive to said actual voltage representative signal and to said reference signal for detecting said critical event.
Claim 12
Dependent Claim
23 words
The UPS system of claim 10, with said predetermined time delay being initiated from a zero-current condition detected in said first transfer switch.
Claim 13
Dependent Claim
49 words
The UPS system of claim 11, with means associated with the power switches of said first transfer switch for sensing the respective voltage drops thereacross, thereby to provide an indication of said zero-current condition upon a transition in said voltage drop occurring concurrently and for all power switches thereof.
Claim 14
Dependent Claim
35 words
The UPS system of claim 12 with static controlled harmonic filtering means operatively connected at the output of said inverter through corresponding power switches controlled concurrently with said gating means being in the UPS mode.
Claim 15
Dependent Claim
31 words
The UPS system of claim 13, with harmonic filter gating means being provided for said filtering means for gating the corresponding power switches in a filtering mode after said predetermined delay.
Claim 16
Dependent Claim
37 words
The UPS system of claim 13, with said filtering means corresponding power switches being gated after said time delay and concurrently with voltage zero-crossing occurring at a location between said first transfer switch and said AC load.
Claim 17
Dependent Claim
51 words
The UPS system of claim 15, with said harmonic filtering means having capacitor means precharged at one of the voltage peak values of said AC power supply; said gating means being enabled following said predetermined delay by the first voltage peak of the same polarity as said precharged capacitor means voltage.
References Cited (Backward Citations)
US4384414A
Cited
US4340823A
Cited
US4388534A
Cited
US4510401A
Cited
US4528457A
Cited
US4788451A
Cited
US4562357A
Cited
US4604530A
Cited
US4553039A
Cited
US4564767A
Cited
US4588900A
Cited
US4560887A
Cited
US4667116A
Cited
US4665322A
Cited
US4634888A
Cited
US4673825A
Cited
US4692632A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-10 | 1996-11-09 | 1997-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-10 | 2000-11-09 | 2001-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-10 | 2004-11-09 | 2005-05-11 | $7700.00 | Window Closed / Lapsed |